Appendix: The mini-drama with Chuck Husick
The origin of this battery research can be traced back to an article I read in an "Annual" issue of Ocean Navigator written by Chuck Husick. What bothered me initially about Chuck Husick's article was the omission of VRLA battery technology: He did not want to cover their "virtues and liabilities". But as I kept reading, more and more red flags kept popping up. Here a couple of the big ones that stuck out like sore thumbs.
Funny Battery Bank Sizing Ideas:
Chuck Husick started a boat energy exercise with a constant 20 ampere load. Common sense would dictate some beefy battery banks and charging systems as a "constant" 20A draw is usually the result of many loads on board. Furthermore, energy draws typically ebb and flow over the course of the day. For example, on our boat, the highest continual draw is at night when the lights and the cabin heat are on. As a rule, the battery bank should be capable of supplying the maximum required current with some safety margin on top of that.
For the sake of argument, let us assume that a boat with a constant 20A draw exists. Using standard guidelines, a 20A load would call for up to 1920 Ah of battery capacity (20A x 24 hrs x 4 = ~650lb of battery). Chuck Husick however decided to use one 275 Ah battery, since his undersized charging system was only capable of delivering 55 amps to the batteries. Why someone would match a battery bank capacity to an alternator instead of the anticipated load is a mystery to me. I have yet to find another resource that advocates such potential battery abuse.
Continuing Mr. Husick's hypothetical exercise, the passage makers were expected to run their diesel engine for 8 hours (!!!) per day. Naturally, given the very low capacity of the battery, these recharges had to be distributed across the day and the night. You know, nothing warms my heart more than the idea of having to treat my diesel engine like a newborn infant and "feed it" four times a day, including when people want to sleep. Furthermore, most auxiliary diesels suffer when run without a significant load - it can cause cylinder glazing and other expensive problems. Even a 120A alternator only draws 5-6hp off your engine.
So, do such "results" have any kind of basis in the real world? Why wouldn't an article for passage makers (the supposed target audience of Ocean Navigator) contain a "real world" exercise with "real" loads (broken down by item) and "real" battery, charging system sizing? There are plenty of resources out there that Chuck Husick without doubt is aware of.
Better yet, he could have created three scenarios for passage makers with boats of differing sizes and luxury levels. Let's face it: Not all of us carry a air conditioner, water maker, or sub-zero refrigerator on board.
Hilarious Battery Charging Ideas:
While every source I have consulted so far recommends minimizing the number of banks to maximize bank capacity (to enhance cycle life by limiting the depth of discharge), Chuck Husick takes a very different tack. He recommends discharging batteries individually and recharging them collectively, even though this will result in lower effective battery capacity.
High discharge rates relative to battery capacity will make the battery go "flat" faster because the available capacity of lead acid cells decreases as a function of amperage draw (i.e. the chemistry in the battery cannot keep up with the current draw). Some types of lead acid batteries are better at overcoming this problem than others. It depends on the lead plate thickness (starter vs. deep cycle), construction (AGM, Gel, flooded/wet cell), and chemistry (alloys, buffers, and so on). Keep in mind that while a flooded starter battery will allow high rates of discharge, it will not tolerate deep discharges at all.
Once a charging source is available, Mr. Husick recommends paralleling the batteries for recharge. But how can you ensure that individually discharged batteries have the same charge level prior to recharge? Inevitably, some cells will be over-charged and others undercharged, as the collective bank is worked to float (the last stage of charging). While small charge differences may not result in immediate and drastic plate damage, the real question is why to discharge individual batteries from a bank in the first place.
Better Performance from Individual Batteries than from a Bank?
Chuck Husick claims that his battery management philosophy will lead to "better performance". Unfortunately, this philosophy runs counter to accepted physical laws and published industry resources. For example, Peukerts equation is used by every battery manufacturer to characterize the load characteristics of their batteries. If Chuck Husick has found a way to get better performance out of individual batteries in a bank rather than the bank as a whole (and therefore bypass Peukerts Effect), I (and the rest of the battery industry) would want to know how.
Furthermore, a properly fused bank will continue to function after a partial failure (i.e. a battery shorting out, causing its fuse to trip) while a cell shorting out in an individual battery will leave you with insufficient voltage to run most electronics on board. In certain situations (storms, harbor entries at night, etc.) this could be pretty disastrous as the crew struggles to diagnose the problem, then to switch the batteries around.
To summarize, Chuck Husick
- ignored very relevant battery technologies
- came up with a battery discharge scenario/charge plan that had no basis in the real world
- ignored physical laws that clash with his battery philosophy
This is why I believe his technical writing should be taken with a grain of salt. He has lived a very interesting life, has earned many certifications, and even has an impressive sounding position at US/Boat. However, I am unsure how any of these qualify Mr. Husick to write competently about marine batteries and how to best utilize them.
What is worse, he has refused to reconcile the inconsistencies between his views and generally accepted theories on optimal battery charging, utilization, etc. Not one shred of evidence has been submitted by him to refute Peukerts Law (which is the only way that his discharging/recharging advice could actually lead to equivalent performance of individual batteries vs. a battery bank), nevermind superior performance as he claimed.
His ignorance regarding objective comparisons between various lead-acid battery technologies is even more appalling. For example, he compares AGM batteries on cycle life to super-premium Surrette/Rolls batteries while also comparing them to entry-level batteries on price. This is a great way to rig a contest. When pressed where to find the Rolls-Royce of marine flooded batteries at a Ford Pinto price, he couldn't.
So what was the point of publishing his original article in Ocean Navigator? Where was the objective editing that most of us depend on when we seek advice? From my discussions with the editorial staff, it became clear that Ocean Navigator does not review articles for technical accuracy. So if something looks funny to you in one of their publications, it probably is. How hard is it to sell snake oil to the gullible?
Time for Letters to the Editor!
Being the engineer I am, I decided to hunker down and write my first letter to the editor. Surprisingly, Ocean Navigator published it (though truncated) along with a reply from Mr. Husick. His replies made me scratch my head in wonderment and I have assembled them on this page.
Thus, my need for Letter II. Admittedly, I had a bit of fun poking at his explanations and Ocean Navigator decided not to print it. Chuck Husick decided to ignore the points he could not argue and wrote a rambling response (included in Letter III).
Most galling was Chuck Husick's cavalier dismissal of Nigel Calder's excellent and clear arguments as mere "opinions" without offering any proof whatsoever that his own views were better. I suppose that would have been difficult since he has yet to find a way to refute Peukerts Law or to find a new Rolls-CS series battery for the price of a budget Trojan cell.
Despite the very real threat of sending my letter straight to the roundfile, I replied with a point-by-point rebuttal in my third Letter to the Editor. As expected, it was not answered or printed either.
The most unfortunate aspect of this dialogue was the lack of specific references to support Chuck Husick's views. Where was the scientific evidence that his proposed battery management is superior? I'm not against exploring new ideas... but the responses he submitted to my queries indicate that he did not follow or understand the links I provided. As threatened in his response to letter II, Chuck Husick has chosen to "withdraw from the discussion" we were having. His qualifications are impressive, but I continue to question a number of his assertions.
His unwillingness to form real arguments by offering scientific proof, relevant personal experience, or even just a bibliography that supports his thoughts is telling. If you attend any seminars that are taught by Chuck Husick you may want to take what he says about batteries with a grain of salt. Considering his inflexibility when presented with overwhelming evidence to the contrary of his views, I'm not sure what value the rest of his presentation might have either. After all, you're there to be educated, not to sift through what may or may not be true.
The resume of Chuck Husick certainly sounds impressive. Not everyone was the president of Chris Craft or sits on the board of US Boat. However, when it comes to practical aspects of a boat and its maintenance, I prefer to stick to someone like Nigel Calder who has made a career of successfully fixing and specifying boats. Please keep in mind: I do not claim to be an lead-acid battery expert - I just happened to build cost models for a living, read a couple of books, and surfed the net for a while to come to a diametrically opposed opinion to the assertions by Chuck Husick.
If someone can enlighten me further, please do not hesitate to contact me. I'll do my best to post the information as quickly as possible.
Constantin von Wentzel